System and a method of recovering and processing a hydrocarbon mixture from a subterranean formation

Abstract

The present invention relates to a method and system for recovering and processing a hydrocarbon mixture from a subterranean formation. The method comprises: (i) mobilizing said hydrocarbon mixture; (ii) recovering said mobilized hydrocarbon mixture; (iii) deasphalting said recovered hydrocarbon mixture to produce deasphalted hydrocarbon and asphaltenes; (iv) gasifying said asphaltenes in a gasifier to generate hydrogen, steam and/or energy and CO 2 ; (v) upgrading said deasphalted hydrocarbon by hydrogen addition to produce upgraded hydrocarbon; and (vi) adding a diluent to said upgraded hydrocarbon, wherein said method is at least partially self-sufficient in terms of hydrogen and diluent.

The invention claimed is: 
     
       1. A method of recovering and processing a hydrocarbon mixture from a subterranean formation, comprising:
 (i) mobilising said hydrocarbon mixture; 
 (ii) recovering said mobilised hydrocarbon mixture; 
 (iii) fractionating said recovered hydrocarbon mixture thereby producing a heavier fraction and at least one lighter fraction from said recovered hydrocarbon mixture, wherein said lighter fraction comprises naphtha, kerosene and light gas oils; 
 (iv) deasphalting said heavier fraction thereby producing deasphalted hydrocarbon and asphaltenes; 
 (v) gasifying said asphaltenes in a gasifier thereby generating hydrogen, steam and/or energy and CO 2 ; 
 (vi) adding a first diluent to said deasphalted hydrocarbon after deasphalting in step (iv), prior to upgrading; 
 (vii) upgrading said deasphalted hydrocarbon by adding hydrogen; and 
 (viii) adding a second diluent to said upgraded hydrocarbon, 
 wherein at least some of said hydrogen added to the deasphalted hydrocarbon is the hydrogen generated in the gasifying step and wherein at least some of said first diluent added to the deasphalted hydrocarbon and at least some of said second diluent added to the upgraded hydrocarbon comprises the lighter fraction obtained directly during fractionating. 
 
     
     
       2. A method as claimed in  claim 1 , wherein said upgrading comprises thermal cracking. 
     
     
       3. A method as claimed in  claim 1 , wherein said upgrading comprises hydrotreating. 
     
     
       4. A method as claimed in  claim 1 , wherein said mobilised hydrocarbon mixture comprises water and hydrocarbon and said mixture undergoes separation to produce separated water and separated hydrocarbon. 
     
     
       5. A method as claimed in  claim 4 , wherein a third diluent is added to said mobilised hydrocarbon mixture prior to said separation. 
     
     
       6. A method as claimed in  claim 5 , wherein said method is at least partially self-sufficient in terms of diluent for addition to said mobilised hydrocarbon mixture. 
     
     
       7. A method as claimed in  claim 5 , wherein said third diluent comprises a lighter fraction obtained directly during fractionating. 
     
     
       8. A method as claimed in  claim 4 , wherein said separated water is cleaned and recycled for steam generation. 
     
     
       9. A method as claimed in  claim 8 , which is at least partially self-sufficient in terms of water for steam generation. 
     
     
       10. A method as claimed in  claim 1 , wherein said deasphalting is solvent deasphalting. 
     
     
       11. A method as claimed in  claim 10 , wherein said method is at least partially self-sufficient in terms of solvent for deasphalting. 
     
     
       12. A method as claimed in  claim 11 , wherein the solvent used in said deasphalting is a lighter fraction obtained directly during fractionating. 
     
     
       13. A method as claimed in  claim 12 , wherein said lighter fraction further comprises propane, butane, pentane and/or hexane. 
     
     
       14. A method as claimed in  claim 10 , wherein the solvent used in said deasphalting is CO 2  generated during the generation of steam and/or during gasification. 
     
     
       15. A method as claimed in  claim 1 , wherein at least some of the CO 2  generated in the method is captured and stored in a subterranean formation. 
     
     
       16. A method as claimed in  claim 1 , wherein at least a portion of the CO 2  produced during said gasification is captured and stored. 
     
     
       17. A method as claimed in  claim 1 , wherein said method of recovery is steam assisted gravity drainage (SAGD). 
     
     
       18. A method as claimed in  claim 17 , wherein steam is generated in the gasifying step and the method further comprises injecting the steam into said formation and/or wherein energy is generated in the gasifying step and the method further comprises applying said energy to generate steam and injecting said steam into said formation. 
     
     
       19. A method as claimed in  claim 1 , wherein said method of recovery is in situ combustion. 
     
     
       20. A method as claimed in  claim 19 , further comprising capturing at least a portion of CO 2  from CO 2  rich gas generated during the in situ combustion. 
     
     
       21. A method as claimed in  claim 20 , further comprising reinjecting a portion of said captured CO 2  into the formation and/or storing at least a portion of said captured CO 2  in a formation. 
     
     
       22. A system for recovering and processing a hydrocarbon mixture comprising:
 (a) a well arrangement comprising a production well for use in recovering the hydrocarbon mixture; 
 (b) a fractionator having an inlet for the hydrocarbon mixture fluidly connected to said well arrangement, an outlet for a heavier fraction fluidly connected to a deasphalter unit and an outlet for at least one lighter fraction, wherein the deasphalter unit is fluidly connected to the fractionator and has an outlet for deasphalted hydrocarbon and an outlet for asphaltenes; 
 (c) a gasifier fluidly connected to said outlet for asphaltenes of said deasphalter unit and having an outlet for steam and/or storage for energy produced during gasification, an outlet for hydrogen generated during gasification and an outlet for CO 2 ; 
 (d) a first diluent addition tank fluidly connected to the outlet for deasphalted hydrocarbon of said deasphalter unit and having an inlet for diluent; 
 (e) a first upgrader fluidly connected to said outlet for deasphalted hydrocarbon of said deasphalter unit and having an inlet for hydrogen and an outlet for upgraded hydrocarbon; 
 (f) a second diluent addition tank fluidly connected to the outlet for upgraded hydrocarbon of said first upgrader and having an inlet for diluent and an outlet for syncrude; 
 (g) a line for transporting the hydrogen generated by said gasifier to said inlet for hydrogen of said first upgrader; and 
 (h) a line for transporting said at least one lighter fraction from said fractionator directly to said inlet for diluent of each of said first and second diluent addition tanks. 
 
     
     
       23. A system as claimed in  claim 22 , further comprising a second upgrader fluidly connected to said outlet for syncrude of said second diluent addition tank and having an inlet for hydrogen and an outlet for further upgraded hydrocarbon. 
     
     
       24. A system as claimed in  claim 23 , further comprising a line for transporting hydrocarbon generated by said gasifier to said inlet for hydrogen of said second upgrader. 
     
     
       25. A system as claimed in  claim 22 , further comprising a separator for separating said recovered hydrocarbon into separated water and separated hydrocarbon, said separator being in between said well arrangement and said fractionator and having an inlet fluidly connected to said well arrangement, an outlet for separated hydrocarbon fluidly connected to said fractionator and an outlet for separated water. 
     
     
       26. A system as claimed in  claim 25 , wherein said outlet for separated water is fluidly connected to a water treatment unit for cleaning water for steam generation. 
     
     
       27. A system as claimed in  claim 25 , further comprising a line for transporting said at least one lighter fraction from said fractionator to said separator and/or to the line transporting recovered hydrocarbon mixture to said separator. 
     
     
       28. A system as claimed in  claim 22 , further comprising a line for transporting said at least one lighter fraction from said fractionator to said inlet of said first diluent addition tank. 
     
     
       29. A system as claimed in  claim 22 , further comprising:
 a separator for separating said recovered hydrocarbon mixture into separated water and separated hydrocarbon, said separator having an inlet fluidly connected to said well arrangement, an outlet for separated hydrocarbon fluidly connected to a fractionater and an outlet for separated water; 
 a second upgrader fluidly connected to said outlet for syncrude of said second diluent addition tank and having an inlet for hydrogen and an outlet for further upgraded hydrocarbon; and 
 a line for transporting said at least one lighter fraction from said fractionator to said separator and/or to the line transporting recovered hydrocarbon mixture to said separator. 
 
     
     
       30. A system as claimed in  claim 22 , further comprising a line for transporting at least one lighter fraction from said fractionator to said deasphalter unit. 
     
     
       31. A system as claimed in  claim 22 , further comprising a CO 2  purifier fluidly connected to said outlet for CO 2  of said gasifier and an outlet connected to a subterranean formation for CO 2  storage. 
     
     
       32. A system as claimed in  claim 22 , comprising a line for transporting steam generated by said gasifier to said well arrangement. 
     
     
       33. A system as claimed in  claim 22 , wherein said well arrangement comprises an injection well and at least one vent well for carrying out in situ combustion. 
     
     
       34. A system as claimed in  claim 33 , wherein said vent well is fluidly connected to said CO 2  purifier. 
     
     
       35. A system as claimed in  claim 33 , wherein an outlet of said CO 2  purifier is connected to said injection well.